serban.b Posted July 30, 2013 Report Share Posted July 30, 2013 Hello, Is there a way to read/write (send) data between 2 plc's via gprs modem, using pcom? I'm using V130 and Siemens TC65 at both ends Thanks in advance! Quote Link to comment Share on other sites More sharing options...
AlexUT Posted July 30, 2013 Report Share Posted July 30, 2013 Hi, What are models of OPLCs you use? How many and what data you wish to send/receive? How many PLCs will be in network? Keep in mind that communication speed is limited to 9600 bps. BR. Quote Link to comment Share on other sites More sharing options...
serban.b Posted July 30, 2013 Author Report Share Posted July 30, 2013 2 PLC's. I want to be able to read/write MB's, MI's between PLC's. There will be 2 pcs V130. Thanks Quote Link to comment Share on other sites More sharing options...
AlexUT Posted July 31, 2013 Report Share Posted July 31, 2013 Hi, You can use MODBUS. After establishing connection via GPRS, or dial, do MODBUS Configuration and enable ScanEX for Slave, or MODBUS Configuration and Read/Write for Master. I hope this helps. BR. Quote Link to comment Share on other sites More sharing options...
serban.b Posted July 31, 2013 Author Report Share Posted July 31, 2013 I know I can use MODBUS, but I asked if there is a way to accomplish a communication between 2 plcs via gprs modem using pcom protocol. thanks in advance! Quote Link to comment Share on other sites More sharing options...
Emil Posted July 31, 2013 Report Share Posted July 31, 2013 Theoretically yes. But you need ot implement PCOM Master in one of them. You have a very good description of PCOM in our site and I guess you can accomplish the task in 2-3 weeks. Compared with Modbus, where the programming can take 2-3 hours... Quote Link to comment Share on other sites More sharing options...
serban.b Posted August 1, 2013 Author Report Share Posted August 1, 2013 OK, Thanks. I cannot use MODBUS, I think. The problem is I have a SCADA application build by me, and it's using only pcom to communicate with 3 plc's. (V130). So, beside that, 2 of these plc's must have a communication bewtween them. Lets say, plc1, plc2 and plc3 and scada. PLC1,2,3 communicate with scada, and plc1 communicate also with plc2, directly, not thru scada. All PLC's are using siemens tc65 for communication, and scada use a internet connection. It's possible for a V130 to establish two connections? - one MODBUS and one PCOM with a single gprs modem? MODBUS for communication with other plc and PCOM for communication with scada. scada reads data from all 3 plc's at 10 sec interval. Thanks! Quote Link to comment Share on other sites More sharing options...
Emil Posted August 1, 2013 Report Share Posted August 1, 2013 No. On GPRS you have only one communication channel. Theoretically, you can switch between Modbus and PCOM once established GPRS connection. But this means that you will have only part time connection between SCADA and PLC and it will be difficult to synchronize between controllers themselfs. Idea - use cellular router instead GPRS modem. It will let you to open 4 communication channels. While one port will be opened for the SCADA, with other ports you can communicate Modbus Master Slave or even better TCP or UDP Raw. If you are interested in such solution, I can give you some more info. Quote Link to comment Share on other sites More sharing options...
serban.b Posted August 1, 2013 Author Report Share Posted August 1, 2013 OK, that is a solution, is the same thing as connecting the plc's to the internet thru cable . I think I just need 2 gprs modems with ethernet. Or, other solution is to connect 2 gprs modems to the PLC, on COM1 and COM2. It could be good to implement FB's for using PCOM with gprs modems connected to plc on serial port. thanks! Quote Link to comment Share on other sites More sharing options...
Emil Posted August 1, 2013 Report Share Posted August 1, 2013 Yes, connecting controller via Ethernet to Cellular router is like connecting it to cable Ethernet. In some cases (depends on routher and network) it's even faster and more stable. Two modems - out of elegancy of this solution, which I'm a little in doubts, I'm not sure if the contfroller can handle such configuration. Again - because of elegancy, we never tried it. Quote Link to comment Share on other sites More sharing options...
serban.b Posted August 1, 2013 Author Report Share Posted August 1, 2013 I understand. Thank you, we will try to use gprs modems with ethernet. Have a nice day! Quote Link to comment Share on other sites More sharing options...
serban.b Posted August 1, 2013 Author Report Share Posted August 1, 2013 I understand. Thank you, we will try to use gprs modems with ethernet and come back with results! Quote Link to comment Share on other sites More sharing options...
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